Spirit Mod seems to be a very nice mod with good music. However, there are currently a few problems I'm seeing with the Starpowder/Stargrass:

1. The decorative foilage of Stargrass appears to block Stargrass Tree saplings from growing, it also messes with the smart cursor for this reason when planting Acorns.
2. Unlike other types of grass which need one pickaxe hit to remove, Stargrass needs three.
3. Block Swap doesn't recognize Stargrass as dirt, so it can be swapped with Dirt Blocks, again unlike other types of grass.
4. Stargrass doesn't like to blend with blocks other than itself and dirt, causing things to look uglier than with regular grass.
(5. Minor nitpick, but the Stargrass Trees not glowing along with the Stargrass seems very weird to me. I don't know if that can be changed.)